Extending Windows Search

07/02/2012

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Applies To: Windows Server 2008

You can extend Windows Search 4.0 with add-ins. Protocol handlers, property handlers, and filters enable indexing additional data stores and file types. Preview handlers enable users to get a preview of the content of a result item without opening the item’s associated application. Toolbars provide easy access to searches. Extending Windows Search in these ways enables you to perform the following tasks:

Windows Search Add-Ins

For a list of supported add-ins and third-party filters, property handlers, and protocol handlers that can be integrated with Windows Search, visit the Windows Search Add-Ins Web page. After you install an add-in and the computer is idle, Windows Search indexes the new file types. Some add-ins require a computer restart.

If you have .NET 3.0 installed (this is the default in Windows Vista but not Windows XP), the .NET 3.0 IFilter is included so .xps files are can be indexed. If you have Windows XP and .NET 3.0 is not installed, you can install the XPS Essentials Pack IFilter instead.

Alternatively, you can create your own add-ins. For more information about how to extend Windows Search by creating your own protocol handlers, property handlers or filters, visit the Windows Search Developer Guide on MSDN.

Disabling Unwanted Protocol Handlers

Administrators can disable installed protocol handlers using Group Policy.

Identify the name of the protocol:

In the Registry Editor, navigate to HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows search\ProtocolHandlers.

Locate the protocol handler you want to disable and note its protocol Name.

Example protocol names: Mapi, OneIndex, SomeProtocol

Add a URL path for that protocol to the Prevent Indexing Certain Paths policy as <protocol name>://{*}/*.

Adding Functionality with Toolbars

If you are interested in providing desktop search entry points in Microsoft Office Outlook 2003 or Microsoft Internet Explorer, your users can use Windows Live Toolbar. From this toolbar, Windows XP and Server 2003 users can add another toolbar to Outlook 2003 to start searches from within Outlook. The underlying search is powered by Windows Search.

Earlier versions of Windows Search supported the MSN Search Toolbar; however, this product is no longer supported by Microsoft.

Microsoft Office Outlook 2007 or later has instant search powered by Windows Search and does not require installation of a separate toolbar.

File Types Indexed by Default

Filters (implementations of the IFilter interface) are required to index the properties and contents of file types. Common filters include those that are already in Microsoft Office™ and that let you index, view, and search file names, metadata, and the contents of .doc or .xls files, for example.

For files with no extension, only basic properties like filename are indexed. On the Indexing Option -> Advanced -> File Types tab, you can add a new extension with just the dot “.” as the value and then choose whether to index properties only or properties and content. As many different types of files may not have a file name extension associated with them, you need to be cautious when indexing the content of such files (for example, if users have a lot of binary files without a file name extension).

In addition, more custom file types can be interpreted and viewed in your preferred format when you create filters or protocol handlers. For file attachments, a limited number of file types are inherently enabled for preview in the Windows Search results window. For additional control, the IT administrator can specify via policy additional file types that are allowed to be previewed via the Windows Search results window.

Windows Search has a filter to index virtually any file type as text, including the file name, the metadata, and the contents of the file. Windows Search indexes some popular file types as text and excludes others, as described below. Users can change these defaults on the on the File Types tab in the Advanced Options dialogue from the Indexing Options Control Panel. For additional control, IT administrators can also prevent certain file types from being indexed via Group Policy.

File Systems and Removable Media Support

Windows Search indexes all drives that specify themselves as either DRIVE_FIXED or DRIVE_REMOVABLE from the WIN32 API GetDriveType Function, except floppy drives. Windows Search can also index digital cameras, card readers, thumb drives, and firewire drives as long as they identify themselves as removable drives.

Natively, WS indexes NTFS drives with notifications, which means that a notifications provider notifies Windows Search that data on the drive has changed so Windows Search can update its index. Windows Search also natively supports FAT drives, but without notifications. In this case, Windows Search periodically crawls the drive looking for changes in data.